Danny,

Great article on something that has long been a pet peev of mine. Most ops 
probably don't even know  where they have to tune a signal for it to be 
exactly zero-beat with the other station. They just tune to a pitch they 
like which may or may not be right on frequency. The K3 sidetone tracks the 
transmitter offset frequency so its extremely easy to zerobeat. You just 
choose a sidetone you like and make sure your receiver matches it when you 
tune in a signal and you're good to go. I think several newer transceivers 
are set up like this but for far too long it was harder than it should've 
been to zero-beat on CW.
Lou Kolb
Voice-over Artist:
Radio/TV Ads, Video narrations
Messages On-hold:
www.loukolb.com
----- Original Message ----- 
From: "Dan B Dyer Jr,/Danny" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Sunday, March 09, 2014 8:03 AM
Subject: 4WeWhoDoCW,AGudRtikl;dd:Zero beating, what is it, how do we do it 
and why should we do itf, By N3EF


> Found this referenced on the QRPL list, and thought it a good simple, wake
> up call-reminder, and one which will cause me to make sure my side tone is
> set as required. HTH, Wb4idu.
> Zero beating, what is it, how do we do it and why should we do it
>
> By N3EF
> First, lets define what zero beating is in general. Zero beat is the
> condition reached during a measurement or calibration when the beat
> frequency between two input signals is no longer detectable. And the beat
> frequency is the frequency produced when two signals are mixed or 
> combined.
> The beat frequency equals the difference or offset between the two
> frequencies. In cw, we are using two audio frequencies to do this. One
> frequency is your sidetone and the other is the pitch of the received cw
> signal which changes as you adjust the tuning dial. In reality, we are not
> listening for the beat frequency. We are listening for the sound of the 
> two
> signals going in and out of phase with each other as the two frequencies 
> get
> close to each other. The two frequencies are so close, you can barely tell
> the difference between them, but you can hear a change in intensity as 
> they
> go in and out of phase with each other adding and subtracting in level. It
> is a "wow...wow...wow.." sound that gets slower and slower as the two
> signals get closer and closer in frequency. It is more pronounced if the 
> two
> signal levels are the same so you may need to adjust your volume and/or
> sidetone level. It is easier to hear the "wow...wow" sound when listening 
> to
> two steady tones, but you can also detect it with one steady tone and one
> switching on and off such as cw morse code. Once you get the hang of it, 
> it
> becomes second nature and you can do it very quickly. Here is the sound of
> two steady tones of around 750hz that start out at 50 cycles apart and
> gradually get closer until they are identical in frequency. The sound of 
> the
> two frequencies going in and out of phase with each other is very
> distinctive. wowwow.mp3   And here is what it sounds like when receiving a
> cw signal as I tune above and below his frequency. You can clearly hear 
> the
> distinctive sound made when the two frequencies are at or very near each
> other. They start out with just the received cw and then you hear my
> sidetone come on. zerobeat.mp3, zerobeat1.mp3, zerobeat2.mp3.
> Now, some of the old timers will tell you that this isn't "real"
> zero-beating. They will tell you that zero-beating is the way we use to do
> it when we had separate transmitters and receivers. Well, they are wrong 
> in
> telling you that. The way they did it was just another way of getting your
> transmit frequency the same as the one you are receiving and was also 
> known
> as zero-beating. The way we do it now is different, but it is still
> zero-beating.
> So why should we zero-beat anyway? Well, if we don't, then we are
> transmitting on two different frequencies and using more bandwidth than
> necessary. You may be QRM'ing another nearby station. The other op may not
> like the pitch of the tones he hears and must use his RIT to change it. 
> The
> other op may be using a narrow filter and not even hear your reply. I
> recently operated with a special event callsign during the Straight Key
> Century Club's first anniversary special event. There were operators from
> each call district using the same callsign appended with their respective
> call district. I was calling CQ 1Kz away from another SKCC operator. 
> People
> answering just threw out their callsign without indicating who they were
> responding to. This is normal and acceptable as a response but some of 
> them
> were 500Hz off frequency directly between us...so who were they responding
> to? And what about the QRM they were causing because they didn't take the
> time and effort to zero-beat. There was no big pile-up going on here as it
> is an often used tactic to be heard when there IS a pile-up. I was amazed 
> at
> how many stations were calling me so far off frequency. Some people don't
> know what zero-beating is, some do but don't know how to do it, and some
> know how but think it is totally unecessary. You don't have to spend a lot
> of time and be exactly on frequency, but you should try to get close. 
> There
> are many aspects of working CW that mark you as a good operator. I think
> zero-beating is one of them.
> There are other ways to zero-beat the other station. If your rig has a
> cw-reverse mode, you can just switch back and forth from cw to cw-reverse
> and adjust your dial until the tone sounds the same in each mode. You can
> tune until you think your close and then turn on a narrow filter and tune
> for max signal level. Some rigs like the Yaesu FT-897 have a zero-beat
> indicator lamp. There are also zero-beat indicator kits that you can adapt
> to your rig. If you have an audio output to your computer you can use one 
> of
> several programs available to do it via your soundcard.
> One other thing you need to be aware of is that some rigs have an 
> adjustable
> sidetone pitch that does not track the rigs transmit offset. If you change
> the sidetone pitch, you can't use it to zero-beat properly.
> I hope this article and sound files have been of help and I hope you
> consider zero-beating an important part of your operating practices.
> Long live CW!